1. Field
One or more embodiments of the present invention relate to a method, medium, and apparatus encoding and/or decoding multichannel audio signals, and more particularly, to a method, medium, and apparatus encoding and/or decoding a residual signal used to up-mix an audio signal.
2. Description of the Related Art
A moving picture experts group (MPEG) surround encoding technique is used to compress audio data in relation to spatial sources. The MPEG surround encoding technique allows an audio signal, compressed according to MPEG audio layer-3 (MP3), MPEG-4 advanced audio coding (AAC), or MPEG-4 high efficiency (HE)-AAC, to be converted into an encoded multichannel surround audio signal. The MPEG surround encoding technique has advantages over other encoding techniques in that this technique maintains backward compatibility to existing stereo equipment, and can be used to reduce bitrates, i.e., a transmission speed, desired for high quality multichannel audio compression while using existing equipment.
According to MPEG surround encoding standards, a core audio signal is conventionally encoded by using any one encoding technique from among bit sliced arithmetic coding (BSAC), AAC, and MP3, while corresponding residual signals are encoded only according to AAC.
Accordingly, when such a core audio signal is encoded with an encoding technique other than AAC, according to the MPEG surround standards, the core audio signal and a residual signal would be encoded by using different encoding techniques. Accordingly, at the decoding end, the core audio signal and the residual signal should be decoded through different decoding techniques. Briefly, herein, the use of the terms encoding technique and encoding method are used interchangeably, with the particular discussion below using the term ‘technique’ for simplicity of discussion to distinguish a method of the present invention from such encoding methods or techniques.
Thus, the inventors of the present invention have discovered that that there is a desire for a method, medium, and apparatus to attempt to overcome such drawbacks and/or problems potentially resulting from such conventionally required different encoding techniques.